1 files changed, 22 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/concepts/var-concept3.C b/gcc/testsuite/g++.dg/concepts/var-concept3.C
new file mode 100644
index 00000000000..c90102848d4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/concepts/var-concept3.C
@@ -0,0 +1,22 @@
+// { dg-options "-std=c++1z" }
+
+template<typename T>
+  concept bool C1 = __is_class(T);
+
+template<typename T>
+  concept bool C2() { return __is_class(T); }
+
+template<typename T>
+  constexpr bool C3 = __is_class(T);
+
+
+template<typename U>
+  requires C1<U>() // { dg-error "" }
+  void f1(U) { }
+
+template<typename U>
+  requires C2<U> // { dg-error "invalid reference" }
+  void f2(U) { }
+
+template<C3 T>  // { dg-error "not a type" }
+  void f(T) { } // { dg-error "" }